RDMA/rxe: Warn if mcast memory is not freed

Print a warning if memory allocated by mcast
is not cleared when the rxe driver is unloaded.

Link: https://lore.kernel.org/r/20220223230706.50332-2-rpearsonhpe@gmail.comSigned-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/sw/rxe/rxe.c

@@ -29,6 +29,8 @@ void rxe_dealloc(struct ib_device *ib_dev)
 	rxe_pool_cleanup(&rxe->mr_pool);
 	rxe_pool_cleanup(&rxe->mw_pool);
 
+	WARN_ON(!RB_EMPTY_ROOT(&rxe->mcg_tree));
+
 	if (rxe->tfm)
 		crypto_free_shash(rxe->tfm);
 }